Which kayak for ocean fishing AND diving?

My first kayak was a Malibu Two which is a great kayak - it's a tandem so you can bring a friend, or you can paddle solo. It's not too heavy, and it's fast. I've caught everything you could catch in these waters from it, and it works fine as a diving yak.

My newer kayak is the O.K. T-13 Angler. It's heavier, more cumbersome, and slower. I honestly prefer the M2.

The T-13 has the rod pod and sonar shield and tons of storage, but if you think you'll be doing any hauling down cliffs or over cobblestone beaches, consider getting something lighter, IMO.

Different strokes I guess....IME:  Tandem diving was horrible. Boat was tippy and the lack of any real storage meant all the gear rides on your lap. Not much fun paddling with spearguns, dry bags, floatlines, game clips full of fish, abs crowding your space. Had to wear the longblades and weightbelt the whole time cause if you tip they go bye bye.  Any kind of surf upon landing and the potential yard sale could be costly.  Bungeeing your gear down is just a big pita also.  Diving solo is a similar experience, little bit more space on deck but still feels crowded, above deck gear acts like a sail in the wind.  Because of its width its cumbersome and harder to handle on land than any narrower yak I've owned.  Paddles OK for being a double but if its primarily paddled as a single you'd be way better off buying a solo.
I got mine dirt cheap and thats the only reason I own it.  Was cool taking my daughter for a paddle every now and then but when it was my primary boat I always wished I had a different one.   
Only fished the M2 solo, and only a couple times....same story.

Getting up and down cliffs or accross beaches and rocks is a pain no matter what kayak you have. Get the yak that best fits your intended use.   

True enough. The T13 Angler has tons of below deck storage and I can strap my cooler into the tank well behind the seat.
2 people in the tandem makes a cliff-haul a lot easier, but yeah, the deck gets crowded.

If the Malibu Two had bigger hatch options it would be a better diving and fishing yak.

You need to try out a lot of hulls to find the one that fits your body style best. On the water your body is married to that hull so you want something that won't fatigue your back and is comfortable to be in when in the swells and such for long periods of time. As far as diving, I would think that a hull that you can slip onto and off of easily is best since you wont be sitting on it for too long. I think diving would requite more storage on the deck as well as opposed to inside storage. I think for diving, those longer narrow Ocean Kayaks seem to be the ticket, although when I test rode the OK's they just didn't fit my body well and seemed a little bit tippy, though I did test only the Prowler 11 and 13 so I do not want to sound negative on OK, there just wasn't that fits-like-a-glove feel with those two models. Good luck.

 I have a OK T13 it's ok,BUT I prefer my old Mallotte paddleboard as long as you're not doing long distances. They are cheap to buy,easy to repair(fiberglass) and fairly light,55lb range. They are old school but very efficient for fishing and diving,LOTS of storage in front and back hatchs. Keep a eye out for used ones in good shape on craigslist,and ncka classified.

I used to have an old mallotte dive board. In the 70's they were Ok but now that hull slappin shit has to go. Get a scupper pro Tw. Fast and easy to get on.

I've got a hobie revo now and I love it.....but it is not a lightweight boat. Before the hobie I had a 12.5ft cobra navigator. This boat was very stable & also lightweight at about 47-48lbs. I used it to ab-dive & yakfish. It tracked pretty good in comparison to my first kayak which was a OK caper. If you can live without the mirage-drive it is one alternative to the OK T-13. I would be hesitant to get a T-13 for use on the ocean due to the rod-pod leakage issue. jim